LOS ANGELES — Kellie Lim knows all too well what it is like to be a very sick child.

Struck with a ravaging bacterial infection that destroys limbs, she became a triple amputee at age 8 and soon faced a life of prosthetics, wheelchairs and often-painful rehabilitation.

But from that suffering, Lim forged a life of achievement. On Friday, she will graduate from medical school at UCLA, and then will begin a residency program at the medical center there.

Her chosen specialty? Pediatrics, with a possible concentration later on childhood allergies and infectious diseases.

“Just having that experience of being someone so sick and how devastating that can be — not just for me, but for my family, too — gives me a perspective that other people don’t necessarily have,” the 26-year-old Michigan native said.

Of all the topics she sampled during medical school, only her work with children left her “smiling at the end of the day.”

Lim carried out her medical training with a determination that awed her professors and fellow students and won her the school’s top prize for excellence in pediatrics.

Opting not to use a prosthetic arm, she showed that she could perform most medical procedures with one hand, including taking blood and administering injections. She lives on her own in an apartment with no special features for the handicapped, and drives a car with only one adaptation: a turning knob on the steering wheel. She is learning to swim, is trying horseback riding and recently went tandem skydiving.

Lim, whose legs were amputated about 6 inches below her knees, gave up her wheelchair years ago and walks so well down the crowded hospital hallways — with a slightly bouncy stride — that new classmates and patients often don’t know for weeks that artificial limbs fill her shoes and pant legs.

“With Kellie, at first you notice her hand is not there. But after about five minutes, she is so comfortable and so competent that you take her at face value and don’t ask questions so much. She has an aura of competence about her that you don’t worry,” said Dr. Elijah Wasson, who supervised Lim during a rotation in internal medicine at Olive View-UCLA Medical Center in Sylmar.

Lim attributes some of her gumption to her childhood bout with bacterial meningitis. The resulting toxic shock, with internal clotting and bleeding, wrecked her extremities, leading to the amputations. When she went back to a Michigan hospital to read her medical file last year, she found an evaluation stating that 8-year-old Kellie Lim had an 85 percent chance of dying of the meningitis.

Her parents urged her not to give up during her four months of hospitalization and the following years of rehabilitation. Just five months after she became sick, Lim returned to regular school in suburban Detroit.

Previously right-handed, she learned to write and do chores mainly with her somewhat-diminished left hand, which lost three fingertips to amputation, after her entire right hand and forearm were removed. She has been fitted with prosthetic arms but does not wear one in public and uses it at home only for rare tasks, such as assembling a desk by herself.

“I hate failing,” she said. “It’s one of those things that’s so ingrained in me.”

That view was intensified by another disability in the family. Her mother, Sandy, went blind in her 20s and, except for not driving, sought to continue as normal a life as possible in raising three children. She cooked, cleaned and walked the youngsters to school.

“She definitely was a great role model for me,” Lim said.

Just before her mother’s death three years ago, Lim promised her that she would finish medical school — a pledge she will fulfill when she and her UCLA classmates take the Hippocratic oath.

“She wanted me to be a pediatrician,” Lim said, “and I know that somewhere out there, she knows I am going to be one.”

Neil Parker, senior associate dean of student affairs at UCLA’s David Geffen School of Medicine, recalled how Lim resisted some early efforts to adapt or substitute medical equipment for her. “I think at the beginning we were perhaps a little at odds, because I wanted to help her a lot with what I felt she needed,” he said. “She wanted me to help her, but only with what she was willing to use.”

Lim was assigned, on her final medical school rotation, to the pediatric allergy and immunology division under the supervision of Dr. Robert Roberts. On a recent Monday afternoon, she did the preliminary interviews and examinations by herself, deftly taking notes, pointing a light into ears, listening to hearts with a stethoscope.

She made no attempt to hide her residual limb, which she maneuvered to hold down papers. Following medical protocol, she briskly washed the right limb and her left hand before touching patients or instruments.

First came a 14-year-old boy, who despite severe asthma, allergies, nosebleeds and migraines wants to play more baseball. He displayed the closed-mouthed shrugging of boys his age, but his mother detailed his middle-of-the-night breathing emergencies. Lim soon spotted evidence of inflamed tissue and recent bleeding in his nose. After a consultation with Roberts, the youth was prescribed a trial of new asthma medicine.

The boy’s mother, Karen St. Louis, said she and her family talked about the doctor during the drive home as a “phenomenal” role model: “The conversation was that you can do anything you put your mind to.”

Out in the world, Lim’s partial arm sometimes attracts odd comments and stares, but her patients have shown overtly negative reactions only a couple of times, she said. Some small children were frightened by it and had to be soothed. Lim said she knows that some parents might be wary of her and that she will have to prove her competence.

“I’m not going to force myself on them in any way, but it still affects me personally,” she said. “It kind of wears you down a little bit.”

Still, Lim clearly identifies with the struggles of families with very ill youngsters.

“It’s very tragic,” she said, “but the parents love their kids and will do anything for them and know so much about them.”